iMac - System slow in morning

I've had my intel Imac 17" for about 6 months now. After about a month of use it has been really slow to wake up in the morning. The system is set to sleep after 20 minutes it goes to sleep a number of times during the day and always comes right back out without issue. But in the morning after being asleep all night it is really slow. By slow I mean almost 3 minutes to come out of sleep mode and then it will take 1 to 5 minutes to respond to mouse actions. I have to reboot the system to clear up this behavior.

I have checked memory and processes and there doesn't seem to be anything eating up system resources.